优点

配置安装简单，使用方便

与云平台集成较好，VPC的方式没有额外的性能损失

缺点

VXLAN模式对zero-downtime restarts支持不好

When running with a backend other than udp, the kernel is providing the data path with flanneld acting as the control plane. As such, flanneld can be restarted (even to do an upgrade) without disturbing existing flows. However in the case of vxlan backend, this needs to be done within a few seconds as ARP entries can start to timeout requiring the flannel daemon to refresh them. Also, to avoid interruptions during restart, the configuration must not be changed (e.g. VNI, --iface values).